Disk Drive

R80 Disk Drive

Pocket Service Guide

EK-OORSO-PS-OOl

R80 Disk Drive

Pocket Service Guide

Prepared by Educational Services of

Digital Equipment Corporation

Copyright ! 1982 by Digital Equipment Corporation

All Rights Reserved

The information in this manual is for informational purposes and is subject to change without notice.

Digital Equipment Corporation assumes no responsibility for any errors which may appear in this manual.

Printed in U.S.A.

This document was set on DIGITAL's DECset-8000 computerized typesetting system.

The following are trademards of Digital Equipment Corporation. Maynard~ Massachusetts:

DEC DECsystem-IO DIBOL lAS OMNIBCS Q-BCS UNIBIJS

DECUS DECSYSTEM-20 Digital Logo LSI-I I PDP RSTS VAX VT

DECnet DECwriter EduSystem MASSBUS PDT RSX VMS

CONTENTS

INTRODUCTION

1 .1 GeneraL ... . 1.2 Field Replaceable Units (FRUs) ... . 2

FRONT PANEL SWITCHES

AND

INDICATORS

2.1 Operator Controls and Indicators.... ... 9

2.2 Front Panel Fault Identification Codes... 10

3

DIAGNOSTIC FAULT ISOLATION AND TROUBLESHOOTING

3.1 Internal Drive Diagnostics... 11

3.2 Fault Isolation... 16

3.2.1 Power Supply Fault Isolation ... 25

4 SERVICING TIPS

4.1 Tips and Reminders... 29

4.1.1 Testing the Write-Protect Function ... 29

4.1.2 Checking Firmware Revision and ROM Set Num bers ... ·29

4.1.3 Spin-Up Delay After Power-On ... 30

4.1.4 Spindle Motor Thermal Timeouts... 31

4.1.5 HDA Fault Isolation... 31

APPENDIX A BINARY TO HEXADECIMAL CONVERSION FIGURES

1-1 Major FRUs... 8

2-1 Fault Identification Codes... 10

3-1 Location of Internal Maintenance Controls and Indicators... ... 11

3-2 Voltage Test Points... 27

4-1 Last Eight Bytes of a ROM... 30

iii

TABLES

1-1 Related Documentation... 1

1-2 FRU/Service Reference Table... 2

2-1 Control and Indicator Functions... ... 9

3-1 Off-Line Procedure to Run Diagnostics... 12

3-2 Procedure to Go Back On-Line... 12

3-3 Sample Run Procedure (Static Logic Test)... 13

3-4 Test-Select Codes... 14

3-5 Prompt and Steady State Codes.. ... 16

3-6 LED Error Codes and Possible Cause(s).. 17

3-7 Power Supply Failure Symptoms... 26

3-8 DC Voltage Tolerances... ... ... ... 27

4-1 Last Byte Address of Each ROM... 30

A-I Binary to Hexadecimal Conversion... 33

1 INTRODUCTION

1.1 GENERAL

This book contains a brief synopsis of servicing informa- tion for the R80 Disk Drive and is written for field ser- vice personnel who maintain this equipment. If more comprehensive information on this subject is needed, re- fer to the documents listed in Table I-I.

Table 1-1 Related Documentation

Document Number

R80 Disk Drive User's Guide

R80 Technical Description R80 Disk Drive Service Manual

RM80 Field Maintenance Print Set

EK-OORBO-UG EK-OORBO-TD EK-OORBO-SV

MP-OOB75

1.2 FIELD REPLACEABLE UNITS (FRUs)

Table 1-2 contains a list of FRUs and service reference data. A reference number has been assigned to each item in the FRU jService Reference table. These numbers are used in Figure I-I and again in Table 3-6. I n the figure, the reference numbers identify major FRUs. In the table. the reference numbers identify possible causes of error codes and faults within the drive. Figure I-I shows the relationship between major FRUs.

Table 1-2 FRU jSenice Reference Table

Ref.

No. Item PN jReference

Drive'power supply.

120 Y, 60 Hz H766A

2 Drive power supply,

220 Y. 50 Hz H766B

3 Motor start capacitor,

115 V, 60 Hz 10-16924-00

4 Motor start capacitor,

220 Y, 50 Hz 10-17217-00

5 Drive power supply

fan. 117 Yac 12-09403-02

6 Front bezel fan.

117 Yac 12-10719-03

7 Adapter fan, \ 15 Yac 1 2-1 1 714-00

8 Belt. 60 Hz 12-\ 2635-03

9 Belt. 50 Hz \ 2-12635-04

10 lD O/READY switch cap \ 2-\ 269 \-00

J 1 ID IjREAOY switch cap 12-12691-01 12 I D 2/READY switch cap 12-12691-02 13 10 3/REAOY switch cap 12-12691-03 14 ID 4jREADY switch cap 12-12691-04 15 10 5jREADY switch cap 12-12691-05 16 10 6jREADY switch cap 12-1 2691-06 17 ID 7/REAOY switch cap 12-12691-07 18 RUN/STOP switch cap 12-12714-00

INTRODUCTION 3

Table 1-2 FR U /Service Reference Table (Cont)

Ref.

No. Item PN /Reference

19 WRITE PROT switch cap 12-12714-01 20 FAUL T switch cap 12-12714-02 21 STA T 1 switch cap 12-12714-30 22 ST AT 2 switch cap 12-12714-31 23 Wedge lamp, 6.3 V 1 2 -1 27 I 6-00 24 Belt tension micro-

switch 12-14011-00

25 H DA speed sensor

(optical switch) 12-16817-00 26 H DA thermal switch 12- 16870-00 27 Gas spring assembly 12- 17072-00

28 Spare parts case 29-23187-00

29 Read/write module 54- 13596-00 30 Operator control

panel module 54-13641-00

31 Microprocessor

module 54- 14012-00

32 I/O cable assembly 70-1878~00

33 Brush ground assembly 70-162 15-00 34 Head disk assembly

(HDA) 70-] 6225-00

35 Wing pivot assembly 70-] 6230-00 36 Motor /brake assembly,

115 V, 60 Hz 70-] 6723-00

Table 1-2 FRU /Senice Reference Table (Cont)

Ref.

No. Item PN /Reference

37 Motor /brake assembly,

220 V, 50 Hz 70-16723-01

38 Motor actuator

assembly 70-16724-00

39 Logic dc power cable

assembly 70-16732-00

40 Logic ac power

harness assembly 70-16733-00 41 Servo preamp cable 70-16735-00 42 40-conductor data

cable (personality

module) 70-16737-00

43 40-conductor data

cable (servo module) 70-16737-01 44 20-conductor data

cable (personality

module) 70-16738-00

45 20-conductor data cable (read/write

module) 70-16738-01

46 50-conductor read/

write cable 70-16739-00

47 Operator control

panel cable 70-16740-00

48 Shock mount assembly 70-16742-00 49 Personality module

with stiffener 70-16975-00

50 Servo module with

stiffener 70-16976-00

INTRODUCTION 5

Table 1-2 FRU /Service Reference Table (Cont)

Ref.

No. Item PN /Reference

51 26-conductor I/O

cable (top half only) 70-16978-00 52 60-conductor I/0

cable (top half only) 70-16979-00 53 Belt tension switch/

HDA positioner motor

harness assembly 70-16980-00 54 Disk drive power cord

assembly, 60 Hz 70-17335-00

55 Disk drive power cord

assembly. 50 Hz 70-17335-01 56 Motor tension spring 74-22440-00

57 Air filter 74-22816-00

58 Belt tension See Chap. 3

adjustment of Service

Manual 59 Servo adjustments See Chap. 3

of Service Manual 60 Drive I/O cables

not connected See Figure

properly 1-1

61 H DA positioner lock Refer to in wrong position Service

Manual 62 Belt tension lever Refer to

in wrong position Service Manual 63 Spindle motor over- Refer to

heated Service

Manual

Table 1-2 FRU /Service Reference Table (Cont) Ref .

. No. Item PN/Reference

64 Ambient room Decrease

temperature too high temperature

65 Speed transducer See Figure

ca ble not connected I-I

66 Read-only test Refer to

failed Service

Manual

67 Positioner motor See Chap. 3

going too slav. of Service Manual

68 Positioner motor See Chap. 3

going too fast of Service Manual 69 Spindle not spinning Refer to Service Manual 70 Cables not connected See Figure

properly I-I

7 J Drive-unsafe Refer to

condition Service

Manual 72 Recalibration failure Refer to

Service Manual 73 Test inhibited by Refer to

drive fault caused Service by previous error Manual

INTRODUCTION 7

Table 1-2 FRU jSenice Reference Table (Cont)

Ref.

No. Item PN jReference

74 Starting and ending Enter address same as for correct

seek test address

75 Jumper for read-only Refer to cylinder formatter Service

utility missing Manual

76 Cylinder address Enter

greater than 560 has correct

been entered address

77 Wrong procedure used Refer to

or wrong value Service

entered Manual

78 Software problem Check

programming

79 Terminator 7009938-00

80 Cables Refer to

Service Manual

81 Opera tor error Refer to

Service Manual 82 Low ac power input . Refer to

Service Manual

RI.FER TO REFERENCE NUMBER 1:\

T,\BLI: I-~ f-OR DESCRIPTIOK

Figure I-I Major FRUs

2 FRONT PANEL SWITCHES AND INDICATORS

2.1 OPERATOR CONTROLS AND INDICATORS Table 2-1 lists the R80 Drive controls and indicators.

Table 2-1 Control and Indicator Functions

Control/ Indicator Action or

Indicator Lamp Indication

RUN/STOP On in RUN Spin-up sequence position begins if no

faults are de- tected RUN/STOP Off in STOP Power to the

position spindle motor is when spindle turned off stops

FAULT On Indicates a de-

vice unsafe or error condition in drive

READY On I ndicates a suc-

cessful (fault- free) spin-up sequence. In- dicator goes off during seek operations.

WRITE On Disables write

PROTect circuits to pre-

vent data from being written.

STATus On or Orf Used in fault code displays

9

2.2 FRONT PANEL FAULT IDENTIFICATION CODES

When the FAULT light comes on, pressing the FAULT switch once causes all of the indicator lamps to light up momentarily as a means of verifying that the lamps are functioning. Then, all lamps except those displaying the fault code go off.

Pushing the FAULT switch the second time stores the identify of the fault in the microprocessor, clears the fault to permit a command retry, and turns off the fault- code display (providing the fault no longer exists).

Some faults are corrected automatically. in which case the FAULT indicator will go off. If the FAULT lamp does not go off automatically, the FAULT switch must be used as described above.

Figure 2-\ contains the fault-code indications.

'AUl T INDICATOR, A'<D RESET SW'TCH

RED

WRITE PROTECT SWITC"

A'<O I,<OICATOR

RU~ STC)P'SWITC~

A'-Ie INDICATO"

VELlO\\

"766 A ... r 0"

-",p 8C .... 0:.

R 1'\ DIAGNOSTIC READ \\RITE ur;SA', WR'TE PROTEe T SPINDLE MOTOR '''-TERlOCK SPINDLE M'2TOP SPEED IMA"D IIIoTER'ACE COMMAIIoO HDA OR SERVO BOARD OVERTEMPERATuRE MICROCODE SERVO DIAGNOSTIC INITIAL RECAL MIC ROPROCESSOR HARDCORE TES'

\ REAO::~~'iATOR

Bg

0'- 0 ...

0,,"

Or-;

or.,

0'- 0110

0'- ON 0,,"

'THE IIIIOICATOR STATE Will BE THE SAME AS IT WAS BEfORE THE FAULT SWITCH WAS PUSHED

,YEllOli'>

\~

r::l

~

Or., ON

0'"

ON 0,,"

Figure 2-1 Fault Identification Codes

STAT' I'<DICATOR

'WHITf

01\;

0'-

0""

0'"

0,,"

STAT 2 INDICATOR

I\\'H'TE

01\;

O~

Or-;

0""

3

3.1

DIAGNOSTIC FAULT ISOLATION AND TROUBLESHOOTING

INTERNAL DRIVE DIAGNOSTICS

Figure 3-\ shows the location of the maintenance con- trols and indicators inside the drive. Tables 3-1 through 3-3 show some procedures using these controls.

MSB LSB

OODCOCOO

Drn~~m ~

E R

~oooo ~

'----v----' LED DISPLAY THUMBWHEEL

ENTER RESET SWITCHES MICROPROCESSOR

SWITCH MODULE

:Z 03S6

Figu re 3-\ Loca tion of Internal Maintenance Controls and Indicators

II

Table 3-1 Off-Line Procedure to Run Diagnostics Step Action

Set thumbwheel switches to FF 2 Push enter switch 3 Push enter switch

again

4 Set thumbwheel switches to 00 5 Push enter switch 6 Push enter switch

again

Results

LEDs will blink FF

LEOs will dis- play steady FF

LEOs will dis- play steady 00 LEDs will dis- play blinking EC until test- select code is entered.

Table 3-2 Procedure to Go Back On-Line

Step Action Results

Set thumbwheel switches to I D

2 Push enter switch LEOs will momentarily display I D and then E7 3 Set thumbwheel

switches to 00

4 Push enter switch LEDs will dis- play 00 and drive will be back on-line

FAULT ISOLATION AND TROUBLESHOOTING 13

Table 3-3 Sample Run Procedure (Static Logic Test)

Step Action Results

Go off-line as LEOs will blink

outlined in EC

Table 3-1 2 Set thumbwheel

switches to 22

3 Push enter switch LEOs will momentarily display 22. If no errors are encountered.

LEOs will then display AA as a completion code. If any- thing other than AA is dis- played. refer to Service Man- ual for correc- tive action.

4 Push enter switch LEOs will blink EC until next test-select code is entered.

Table 3-4 contains a list of the various internal diagnostic tests and the corresponding test-select codes. Although these codes are listed alphanumerically. it is recommend- ed that the entire unit test (initiated by test-select code 25) be run first. Table 3-5 lists the prompt codes that oc- cur during diagnostic tests.

Table 3-4 Test-Select Codes

Test- Select Code

01

02 03 04 05 06 07 08 09

OA OB OC

00

OE OF

II 12 13 14 15 16 17

Test

Examine diagnostic extended- status area utility

Examine previous error utility Examine drive-state utility Examine seek-counters utility Memory-examine up utility (refer to Service Manual for parameters)

Memory-examine down utility (refer to Service Manual for parameters)

Three-module bus test

Microprocessor module bus test Microprocessor and personality module bus test

Microprocessor and servo module bus test

Personality module micro- sequencer test

Sector /byte counter test Operator control panel test Head-select multiplexer test General purpose counter test Track counter test

Read/write fault force test Servo position loop test Servo velocity loop test Servo functional test Random seek test

Seek - seek test with input parameters (refer to Service Manual for parameters)

FAULT ISOLATION AND TROUBLESHOOTING 15

Table 3-4 Test-Select Codes (Cont)

Test- Select Code

18 19

IA IB IC ID IE IF

20 21 22 23 24 25 26 27 CF FF

Test

Seek - seek test with fixed parameters

I ncremental seek test with input parameters (refer to Service Manual for parameters) Incremental seek test with fixed parameters

Read-only test Write/read test Return on-line Spindle control utility Head-select and seek utility (refer to Service Manual for parameters)

Maintenance controls and in- dicators test

Read-only cylinder formatter utility

Logic tests Servo tests Read/write tests Entire unit test

Servo velocity adjustment utility

Static servo test

Set loop mode utility (refer to Service Manual for parameters) Enter diagnostic mode

Table 3-5 Prompt and Steady State Codes Code

Blinking EC . (I I 10 I 100)

Blinking 0 I, 02,03,or 04

Blinking EE (1110 1110)

Steady state AA

Steady state E7

Significance

Indicates that firmware is waiting for a test-select code.

Indicates the number of . the current input para-

meter required by the diagnostic utility or test.

Indica tes an invalid test- select code has been entered. Requires entry of a valid test-select code.

Indicates test completion.

Return to the EC prompt before running another test.

Indicates that the firm- ware is actively executing a test.

3.2 FAULT ISOLATION

Table 3-6 provides a list of the LED error codes for the drive and the errors they represent. The numbers in the right-hand column correspond to reference numbers in Table 1-2 and denote the most likely causes of the error.

FAULT ISOLATION AND TROUBLESHOOTING 17

Table 3-6 LED Error Codes and Possible Cause(s)

Error Possible

Code Error Cause(s)*

00 Microprocessor

self-test error 31,49,42,1

01 Spindle motor 8,25,31,29,

timeout error 46,36,3,1, 39,40

02 Spin-up too 5,36,8,25.

slow error 31,34

03 Spindle not 5,36,8,25,

accelerating 31,34

04 Spin-up too 5,36,8,25,

long error 31,34

05 Seq uence-hold / seq uence-pick

error 60,49

06 Microcode error 31

OA

I nvalid inter- face command

error 49,31,42

II t Wrong peak entering detent

error 50,31,43,34

12 Servo active 50,31,43,41,

PLO error 34,1

13 No fine track 50, 31, 43, 34,

error 1

14t Servo speed or 50,31,43,34,

direction error 1

*See Table 1-2

tlndicates a servo problem

Table 3-6 LED Error Codes aod Possible Cause(s) (Coot)

Error Possible

Code Error Cause(s)*

15t Seek/recal 61,50,31,43,

timeout error 53,34,1

16t Guard-band 50,31,43,34,

error 1

17t Track counter 50, 31,43, 34,

underflow error 1

JA I nvalid cylinder 49,31,42,32,

address error 52

23 Spindle motor

interlock error 62,31,24,53

24 Servo inactive 50,31,43,41,

PLO error 34,1

25t Servo detected 50,31,43,34,

off-track error 1 26 Spindle speed

error 5,64

27 HDA overtemper- 5, 64, 65, 26,

ature error 29,46,31

28 Servo module

overtemperature 6, 64, 50, 43,

error 31

30 Write current and no write-

gate error 29,31,46,34

31 Read and write 49,31,44,32,

error 51,52

*See Table 1-2

tlndicates a servo problem

FAULT ISOLATION AND TROUBLESHOOTING 19

Table 3-6 LED Error Codes aod Possible Cause(s) (Coot)

Error Possible

Code Error Cause(s)*

32 Read/write while 31, 49, 29, 44, faulted error 46,45,34

33 Data separator / 31.29,49,46,

encoder error 44

34 W ri te-precom pen-

sation error 31,49.42

35 Write and write- 29,46.45,31,

unsafe error 34

36 Head-short error 29,46,45,31,

34

37 Write gate and 29,46,45,31,

no write-current 49.44,32,51,

error 34

3g Read and multi-

chip-select 29,46,45,31,

error 34

39t Write and off- 50, 31, 43. 41,

track error 34

3A Write and write-

protected error 31,30,47 46 False drive

fault condition 31,50 51 Sector /byte

counter error 31,50,43

53 Personality

module micro-

sequencer error 49,31,42

*See Table 1-2

t I ndicates a servo problem

Table 3-6 LED Error Codes and Possible Cause( s) (Coot)

Error Possible

Code Error Cause(s)*

54 Multiplexer

head-select 31,49,29,44,

error 46

57 RA M 1 general purpose counter

error 31

58 RAM 0 general

purpose counter

error 31

60 Read/write head- 31,49,29,44,

select error 46,45,34

61 Data port preset

error 49,31,42

62 Read-only test

overall read 29,31,49,44,

error 46,45,34

63 Read-only test

partial read 29,45, 34,46,

error 31,44,49

64 Read/write test

guard-band error 50,31,43,34

65 Sector timeout 50,31,43,49,

error 44

66 Read-only test read and no

enable error 59,50,34

67 W rite test not

executable error 66

*See Table \-2

t I ndicates a servo problem

FAULT ISOLATION AND TROUBLESHOOTING 21

Table 3-6 LED Error Codes and Possible Cause(s) (Cont)

Error Possible

Code Error Cause(s)*

6A Write/read test

overall read 29,31,49,44,

error 46,45,34

6B Write/read test

partial read 45,29,46,31,

error 44,49

6E Write/read test read and no

enable error 59,50,34

70 Read/write

control-select

error 31,49,42

71 Utility head-

select error 31

7C Too slow seek

error 67

7D Bad seek count 50,31,43,34,

overflow error 1

7E Too fast seek

error 68

7F Spindle not

spinning error 69

80 ROM set error 31

85 RAM 0 error 31

86 RAM 1 error 31

87 ROM 0 checksum

error 31

*Scc Table 1-2

tlndicates a servo problem

Table 3-6 LED Error Codes and Possible Cause(s) (Cont)

Error Possible

Code Error Cause(s)*

8A Module interlock

error 70

8B Discrete port-

enable error 31

8F ROM I checksum

error 31

97 ROM 2 checksum

error 31

9F ROM 3 checksum

error 31

AO Read and write 31,49,29,42,

safety error 44,46.45,34

A3 Forced read

and write error 31,49,45,42 A4 Forced write

current and no

write gate error 31,49,42 A5 Forced write

gate and no write current

error 31,49,42

A6 Forced separa-

tor

I

^encoder

error 31

A7 ROM 4 checksum

error 31

ABt Outer guard- 50,31,43,34,

band seek error 1

·See Table )-2

t Indicates a servo problem

FAULT ISOLATION AND TROUBLESHOOTING 23

Table 3-6 LED Error Codes aod Possible Cause(s) (Coot)

Error Possible

Code Error Cause(s)*

BO Three-module

microprocessor

bus error 31

B1 Three-module

personality

bus error 49,31,42

B2 Three-module

servo bus error 50,31,43 B3 Microprocessor

module bus

error 31

B4 Personality

module bus

error 49,31,42

B5 Servo module

bus error 50,31,43

C2 Fine-track

status error 50,31,43

C3 Fine-track

overrange error 50,31,43

C4 Fine-track

underrange error 50,31,43 C5 Off-track status

error 50.31,43

C6 Off-track

overrange error 50,31,43

C7 Off-track

underrange error 50,31,43

*SeeTable 1-2

t I ndicates a servo problem

Table 3-6 LED Error Codes and Possible Cause(s) (Cont)

Error Possible

Code Error Cause(s)*

CB Acceleration-

status error 50,31,43

CD Track counter

error 50,31,43

Dot Recalibration

error 50,31,43,34

Dlt Outer guard-band

status error 50,31,43,34

D2t I nner guard-band

status error 50,31,43,34

D3t Seek into outer 50,31,43,34,

guard-band error 1 D4t Outer guard-band

status not true 50,31,43,34

error 1

D5t Recal from outer 50,31,43,34, guard-band error 1

D6t Two-track seek

to track 560 50,31,43,34,

error 1

D7t Seek into inner 50,31,43,34,

guard-band error 1 D8t Inner guard-band

status not true 50,31,43,34,

error I

D9t Recal from inner 50,31,43,34, guard-band error I

*See Table 1-2

t I ndicates a servo problem

FAULT ISOLATION AND TROUBLESHOOTING 25

Table 3-6 LED Error Codes and Possible Cause(s) (Cont)

Error Code Eot EI

Error Random seek error

Seek check error EA Cannot run test,

drive-faulted error EE

EF

Entry error F.E. entered in- valid cylinder- address error

FE Thumbwheel-

switch error

*See Table 1-2

tlndicates a servo problem

3.2.1 Power Supply Fault Isolation

Possible Cause(s)*

50,31,43,34, 1

71,72

73 74, 75

76

31

Power supply failure symptoms are listed in Table 3-7.

Power supply voltages can be measured on the circuit modules at the connector pins indicated in Figure 3-2, and the tolerances for these measurements are given in Table 3-8.

Table 3-7 Power Supply Failure Symptoms

Symptom Check

+

5 volt indicators

WRITE PROTect switch

± 12 volt LEOs

FAULT indica- tor off. all other operator control panel indicators on

Action

Check that the operator control panel indicators and the internal LEO display flash on momen- tarily when power is applied to the drive.

The flash will indicate that

+

5 volts is present.

Check that

+

5 volts is present at the operator control panel WRITE PROTect switch. The WRITE PROTect switch should light when pushed if

+

5 volts is present and the drive is on- line.

Check that the two 12 volt LEOs on the servo module (next to the heatsink) are on. When lit, they indicate that both

+

12 and -12 volts are present.

Check to see if only the FAULT indicator on the operator control panel is off. This condition occurs only when the DC LOW signal is asserted.

Possible causes could be the power supply, micro- processor module, or servo module.

FAULT ISOLATION AND TROUBLESHOOTING 27

PERSONALITY

J

MODULE POWER

J205 GROUND SUPPLY

PINS 4. 5. 6. 9 J701

"5 J205

1\

1.2.3 1.2.3

MiCROPROCESSOR

I

MODULE J702 DC LOW J306

1 1

~300

PINS 9. 10. 12. ^GROUND 14. 17. 18 -5.2

13. 14 15. 16

SERVO MODULE

~

J703

-24 J403

7 11

J403 GROUND

·24 13 PINS 5. 9. 12.

9 14. 16

CZ·()416

Figure 3-2 Voltage Test Points

Table 3-8 DC Voltage Tolerances DC Vol-

tages

+5 -5.2 +24 -24 DC Low

Acceptable Tolerances

± 0.2 volts

± 0.2 volts +3, -I volts + I, - 3 volts

Test Points (See Figure 3-2)

Pins I, 2, or 3 of J205 Pins 15 or 16 of 1306

Pin 13 of J403 Pin II of J403 Pin I of J306

4 SERVICING TIPS

4.1 TIPS AND REMINDERS

The following paragraphs describe some general trouble- shooting tips that may be useful when isolating faults in the R80. Reference to Digital Tech Tips will also prove helpful.

4.1.1 Testing the W rite- Protect Function

The following procedure provides an easy means of checking the write-protect function while the drive is in the functional mode.

I. Spin-down the drive.

2. Push in the WRITE PROTect switch.

3. Spin-up the disk. If the write-protect function is working, the F AU L T indicator will light and the in- ternal LEDs on the microprocessor module will dis- play an error code of 6A.

4. Push the FA U L T switch to enter the fault display mode. The operator control panel will display a R/W diagnostic fault code. Both the FAULT and STAT 1 indicators should be on.

5. Push the FA U L T switch again to clear this fault condition.

6. Release the WRITE PROTect switch.

4.1.2 Checking Firmware Revision and ROM Set Num- bers

The firmware revision and ROM set numbers are located in the last few bytes of each ROM. Table 4-1 lists the last address of each ROM and Figure 4-1 shows what is contained in the last eight bytes of each ROM.

The easiest way to examine these numbers is by using the memory-examine down utility. To access this utility, use test-select code 06. Enter the address of the last byte of the ROM to be examined. Next, push the ENTER switch to examine each byte location starting with the last byte in the ROM.

29

Table 4-1 Last Byte Address of Each ROM

Address of ROM Last Byte

o

^07FF

I OFFF

2 17FF

3 IFFF

4 27FF

5 2FFF

REV I REV I ROM I ROM I I ONES I ZEROS I

HIGHI LOW I ~~JH I ~6~ IfJ~3~ED)1 COLUMNICOLUMNl ~~~CK

BYTE I BYTE I BYTE I BYTE I I CHECK I CHECK I

CZ·Q41;

Figure 4- I Last Eight Bytes of a ROM

4.1.3 Spin-Up Delay After Power-On

When spinning up the disk drive after a power loss, a 40- second delay will occur before the drive will begin a spin- up cycle under either of the following conditions:

• When RUN/STOP switch is already depressed at power-on .

• When RUN/STOP switch is pushed in within three seconds after power-on.

This 40-second delay will occur regardless of whether the power loss is due to a power failure or to a normal circuit breaker power-down.

SERVICING TIPS 31

4.1.4 Spindle Motor Thermal Timeouts

The R80 Engineering Specification calls for a three-min- ute waiting period between successive start-up cycles of the spindle motor. This waiting period is required to pre- vent the spindle motor from overheating and opening an internal thermal switch in the motor.

A spindle motor thermal timeout may be caused by fre- quent spindle motor start-up or loss of cooling due to a fan failure.

If the spindle motor thermal switch opens, it will cause a spin-up fault on the operator control panel and an LED error code display of 01, 02, 03, 04, or 26.

To recover from a spindle motor thermal timeout, check the fans first. If the fans are operating, let the motor cool off for 10 to 15 minutes while power is applied to the drive.

4.1.5 HDA Fault Isolation

Voltage checks can be used in some cases to determine whether or not an HDA problem actually exists. If it ap- pears the the HDA is defective, check the voltages ap- plied to the H DA before replacing the unit. If all power supply voltages are present and within the specified tol- erances, - 4 volts should be present on pins 7 and 8 of J601 on the HDA. Also,

+

6 volts should be present on pins 9 and 10 of J601. If either of these voltages are missing or incorrect. the problem will likely be found in the associated voltage regulators located on the read/write module and not in the HDA itself.

Also check for - 8.2 volts on pin 2 of J602 on the HDA.

If this voltage is missing or incorrect, the problem will usually be found on the servo module between the - 12 volt regulator and J401.

APPENDIX A

BINARY TO HEXADECIMAL CONVERSION

The LED display on the microprocessor module consists of eight LEDs in a row which are read as two hex- adecimal digits. Use Table A-I to convert the binary LED code into hexadecimal.

Table A-I Binary to Hexadecimal Conversion

Hexa- Binary decimal

0000

a

0001 I

0010 2

001 I 3

0100 4

0101 5

0110 6

0111 7

1000 8

1001 9

1010 A

1011 B

1100 C

1101 0

1110 E

1111 F

33